.box1 {
  background-color: red;
}

.box2 {
  background-color: green;
}

.box3 {
  background-color: cyan;
}

.box4 {
  background-color: blue;
}

.box5 {
  background-color: purple;
}

.box6 {
  background-color: orange;
}

.box7 {
  background-color: skyblue;
}

.box8 {
  background-color: pink;
}

.box9 {
  background-color: yellow;
}

.box1 {
  width: 300px;
}

.box1 .box2 {
  width: 200px;
}

.box1:after {
  content: '';
  display: block;
}

h1 {
  width: 999px;
  height: 0.0999px;
}
